1. Field of the Invention
The present invention relates to a method for reducing noxious sulfur species in pipelines using an effective amount of a sulfur scavenger composition, where a fluid flowing through the pipeline includes an aqueous phase and an organic phase and the composition is adapted to reduce noxious sulfur species in both the aqueous phase and the organic or oil phase.
More particularly, the present invention relates to a method for reducing noxious sulfur species in pipeline, especially pipelines with low flow rate, including administering to the pipeline at its start or at one or more locations along is length an effective amount of a sulfur scavenger composition including a water soluble sulfur scavenger and an oil soluble sulfur scavenger, where a fluid flowing through the pipeline includes an aqueous phase and an organic phase and where the composition is adapted to simultaneously reduce noxious sulfur species in both phases in the pipeline. The present invention also relates to compositions including water, a water soluble sulfur scavenger, an oil soluble sulfur scavenger and a surfactant or emulsifier present in an amount sufficient to produce a stable, homogeneous composition.
2. Description of the Related Art
Sewage collection systems for sewage lines include force mains that force the sewage to travel up a grade or hill. In these force mains, the fluid flow becomes laminar causing a slime layer to build up on the pipe walls. In this biomass or slime layer, sulfate reducing bacteria (SRBs) begin to grow and produce H2S. Once produced in the biomass or slime layer, the H2S migrates into the aqueous phase, but while in the slime layer, the H2S can and does cause pipe corrosion. Thus, the H2S produced in the slime layer is responsible for a foul smelling aqueous phase and the build up of H2S in overhead spaces and is responsible for pipe corrosion.
Current treatment methods and composition have focused on removing H2S from the aqueous phase, with either no success or limited success, because the root cause of H2S production was not addressed.
The same problems found in sewages lines is also found in any pipeline through which a bi-phasic mixture is being transmitted and where the flow characteristics in the pipeline or a portion thereof assumes a laminar flow or a reduced flow rate sufficient to permit phase separation with the organic phase adhering to the pipeline walls forming a oil layer.
Thus, there is a need in the art for a sulfur scavenging composition and for methods for its administration into pipelines such as pipelines associated with sewage collection systems or the transportation of any fluid including an aqueous phase and an organic or oil phase that is capable of reducing noxious sulfur species including H2S in both phases, assisting to retain organic materials in the aqueous phase, reducing odors and/or reducing pipeline corrosion problems.
The solution to the above problems was to combine a water soluble hydrogen sulfide or sulfur scavenger and oil soluble hydrogen sulfide or sulfur scavenger in the presence of an amount of a surfactant or emulsifier or mixtures thereof to produce a homogeneous treating composition. The oil soluble components are adapted to partition into the organic phase and into any organic layers coating walls of the pipeline such as a slime layer in sewage pipelines reducing transference of noxious sulfur species such as H2S into the aqueous phase; while the water soluble components are adapted to partition into the aqueous phase removing any transferred noxious sulfur species such as H2S therein.